Unable to mock Eclipse IProject using release prior to 4.12

[tobous]

With the currently used release 4.8, I was unable to mock the Eclipse class org.eclipse.core.resources.IProject or its implementations.

When trying to create a mock, EasyMock runs into a NoClassDefFoundError for org/eclipse/core/runtime/IPluginDescriptor (see stacktrace below).

The cause of this issue seems to be that the class IPluginDescriptor has been deprecated and is no longer included in the default Eclipse artifacts since release 4.6. As a result, I was unable to either mock IProject nor create an IProject stub implementation.

From my testing, this issue seems to be resolved when using Eclipse 4.12 or later.

Steps to Recreate

1. Run a test trying to mock a org.eclipse.core.resources.IProject object.

import org.eclipse.core.resources.IProject;

...

IProject project = EasyMock.createNiceMock(IProject.class)
EasyMock.replay(project);

Expected Behavior

The test runs, creating an IProject mock object.

Actual Behavior

The test fails with a NoClassDefFoundError for org/eclipse/core/runtime/IPluginDescriptor.

Stacktrace

I notices this while trying to mock the necessary calls for FileActivityConsumer.updateFileEncoding(String, IFile). The stacktrace is based on a modified test, so this exact stacktrace won't be reproducible on the master. But the issue can easily be reproduces using the setup given above.

org/eclipse/core/runtime/IPluginDescriptor
java.lang.NoClassDefFoundError: org/eclipse/core/runtime/IPluginDescriptor
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
	at java.lang.Class.privateGetPublicMethods(Class.java:2902)
	at java.lang.Class.getMethods(Class.java:1615)
	at sun.misc.ProxyGenerator.generateClassFile(ProxyGenerator.java:451)
	at sun.misc.ProxyGenerator.generateProxyClass(ProxyGenerator.java:339)
	at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:639)
	at java.lang.reflect.Proxy$ProxyClassFactory.apply(Proxy.java:557)
	at java.lang.reflect.WeakCache$Factory.get(WeakCache.java:230)
	at java.lang.reflect.WeakCache.get(WeakCache.java:127)
	at java.lang.reflect.Proxy.getProxyClass0(Proxy.java:419)
	at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:719)
	at org.easymock.internal.JavaProxyFactory.createProxy(JavaProxyFactory.java:30)
	at org.easymock.internal.MocksControl.createMock(MocksControl.java:98)
	at org.easymock.internal.MocksControl.createMock(MocksControl.java:73)
	at org.easymock.IMocksControl.mock(IMocksControl.java:44)
	at org.easymock.EasyMock.niceMock(EasyMock.java:202)
	at org.easymock.EasyMock.createNiceMock(EasyMock.java:394)
	at saros.project.FileActivityConsumerTest.setUp(FileActivityConsumerTest.java:79)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.internal.runners.MethodRoadie.runBefores(MethodRoadie.java:133)
	at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:96)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:310)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:131)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.access$100(PowerMockJUnit47RunnerDelegateImpl.java:59)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner$TestExecutorStatement.evaluate(PowerMockJUnit47RunnerDelegateImpl.java:147)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.evaluateStatement(PowerMockJUnit47RunnerDelegateImpl.java:107)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:298)
	at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
	at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:218)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:160)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:134)
	at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
	at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
	at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:136)
	at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:117)
	at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
	at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
	at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)
	at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
	at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
	at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
	at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:118)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
	at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
	at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
	at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:412)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.eclipse.core.runtime.IPluginDescriptor
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
	at org.powermock.core.classloader.MockClassLoader.loadClassByThisClassLoader(MockClassLoader.java:100)
	at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass1(DeferSupportingClassLoader.java:147)
	at org.powermock.core.classloader.DeferSupportingClassLoader.loadClass(DeferSupportingClassLoader.java:98)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
	... 73 more

[tobous]

@m273d15 Do you know what would be necessary to update to Eclipse 4.12 or newer and how much effort this would approximately take?

[m273d15]

We have to check whether the SWTBot version (2.7) we are currently using is compatible. Therefore, running STF tests is necessary. With the switch from 4.6 to 4.8 I just had to rename a button. I have to test which changes are required.

I would expect that there is a workaround (require an additional eclipse bundle that contains the interface) for this issue.

[tobous]

I would expect that there is a workaround (require an additional eclipse bundle that contains the interface) for this issue.

I couldn't find anything when searching online. But I already have a workaround for my specific case, so this isn't urgent.

I don't see a general reason why not to update to Eclipse 4.12 to stay at least somewhat up to date (so that we are only one year behind the release cycle instead of 2). But this isn't a pressing issue.